[REQUEST] Lenovo Z580

Hi folks,

I've a Lenovo Z580 with broadcom 802.11n wifi card. With 8.1, it is simply useless, freeze my laptop everyday.

desired card:
Intel Network 7260.HMWG WiFi Wireless-AC 7260 H/T Dual Band 2x2 AC+Bluetooth HMC
Current card: Broadcom 802.11n
OS: windows 8.1
Laptop: Lenovo z580
Current BIOS: 5FCN35WW
Backup of my BIOS:
https://dl.dropboxusercontent.com/u/4691...CN35WW.rom

Please help me use this laptop for a while!
(Will it ruin my warranty? just asking, I'm desperate)